Zinc and copper in an electrolyte generate electricity for a light-emitting diode.

The homemade potato battery

That’s what you need in this potato experiments:

3 potatoes

3 Cent Coins

3 screws and washers made of zinc (from the hardware store or from Dad’s tool box)

4 cables (cable or crocodile wire, insulation at the ends)

1 LED (this time without the resistor!)

1 knife

Here’s how:

Only once the potatoes are cut flat on one side – then they are better. Then each potato into two opposite slits are cut. In the right slot in each one cent coin is in the left or bolt washer. When metal components must lie far apart and should not touch. Now the potatoes as in the image shown in series.

When connecting, make sure that the potatoes are so aligned as shown and will always create a connection between zinc and copper. When you connect the LED note that LEDs are polarized components. The longer pin must be connected to the coin.

What happened?

Can not generate much electricity your home-built battery – but for an LED that consumes very little energy, it is enough. The circuit is closed the potato battery, a chemical reaction takes place between the two metals, copper and zinc and the juice of the potato. Due to the chemical reaction, the electrons begin to flow through the cables.

Whydo they do that?

Zinc and copper are different, “noble”. If two such different metals brought into the solution of an electrolyte (the potato), they turn into electrodes – ie in a positive and a negative pole. Because the zinc atoms bind their electrons tightly, less than copper atoms, are the electrons from zinc to copper. And this electron flow is nothing more than
Current. Alternatively you can use instead of a potato and a lemon or an apple.

After trying to throw the potatoes – they are no longer suitable for consumption!

In this experiment we need a piece of zinc (eg, a strip has been cut from a piece of zinc metal) and a piece of copper, this can be a 1 or 2 cent coin. The coin and the piece of zinc be put into a potato.

Now be attached to the coin and the piece of zinc and held a cable to the terminals of an earphone. You can rustle it in earphones to hear clearly and crack, the proof that rests on the two metals a voltage. We measure the voltage with a multimeter, we note that about 0.8 – 0.9V voltage can be generated.

This as a “crackling potato” experiment is known as an apple or other fruit. The point is not that a potato or a piece of apple between the zinc and copper coins were fixed, but that an electrically conductive fluid between the two metals is different.

For the proof we have even a meter (a digital voltmeter) connected to both ends of the metal and kept in tap water. Here we already measured 0.69 V, we give more salt in the water increases the voltage to about 0.73V. Even a finger of our hands, placed on two metals generates a voltage (about 0.5V).

Potato Experiments For Kids: Why here creates an electrical voltage?

Both the zinc and the copper ions enter into the solution (water, “potato juice”, body fluid) from, so these are the zinc zinc ions, copper ions in copper up. When zinc

but go more ions into the solution. The ions are electrically charged positively, electrons are back with a negative electrical charge. Therefore, the negative electrically charged piece of zinc than the piece of copper, an electrical voltage is established, we can measure.

If you join now both pieces with an electrical conductor, the excess electrons move from the zinc to copper, a current flows. This is for example through the earphones and be audible pops and crackles, by opening the contacts to the handset and close repeatedly.